Third Brake Light Problem

[02GreenTJ]

Today I was trying to install a center cap brake light, so I spliced the wires onto a cheap harbor freight 2 inch LED and the light won't work. Does anyone have any thoughts or tips for the wiring? Not sure if I have a bad light or there is more to it than cutting the wires and reattaching them with the new light?

 

[Boinked]

Have you tested the light on the battery to insure that it is working before installing. It is harbor freight.

 

[OctaviousMonk]

I second that. Check the light and then check all your connections. It’s not a complicated system and should be easy to work out.

 

[02GreenTJ]

Yes it lights up fine

 

[02GreenTJ]

It's literally just the two wires I don't need any harnesses correct?

 

[Boinked]

Also while i am thinking about it. You can hook up a test light to the factory wires and hit the brakes.

Remember leds will only work when the hot is connected to the hot. IE poliraty matters.

 

[Boinked]

It's literally just the two wires I don't need any harnesses correct?

You need 12v positive and a ground.

 

[02GreenTJ]

How do I create a ground please forgive my lack of knowledge for electricity

 

[02GreenTJ]

Doesn't the ground already exist in the tailgate

 

[Boinked]

There should be 2 wires from the third brake light. One is 12v positive one is negative or ground. (Same thing different name)

 

[02GreenTJ]

I have those both set up correctly but no light

 

[02GreenTJ]

https://www.quadratec.com/products/12066_8000.htm This is exactly like what I have

 

[Boinked]

You can try 2 things.

1 Switch the wires and test.

2 test the light directly to the jeep battery to make sure that it works.

 

[02GreenTJ]

I have done both haha multiple times

 

[Boinked]

So assuming that the light works when connectedto the battery.

Also assuming that your regular brake lights work.

If you have a multi meter and a second person. Have them hold the brakes while you test the wires for voltage.

 

[02GreenTJ]

The wires have voltage we did that too I am really stumped

 

[Boinked]

The wires have voltage we did that too I am really stumped

If the wires have voltage and the light works on the battery. But it doesn't work when connected to the wires with voltage. Then you sir have some weird stuff going on.
The only thing that comes to mind is that you dont have enough power going through the wires to light it up. But it should. Now im confused as you

 

[02GreenTJ]

If the wires have voltage and the light works on the battery. But it doesn't work when connected to the wires with voltage. Then you sir have some weird stuff going on.
The only thing that comes to mind is that you dont have enough power going through the wires to light it up. But it should. Now im confused as you

Haha thanks for the help sort of a weird thing going on. I will consult some experts in the mean time if anyone has any thought feel free to let me know.

 

[OctaviousMonk]

Try cleaning up the four contact pads that make the electrical connection when the tail gate is closed. Two will be on the door and two on the Jeep tub. There may be some corrosion or something else making the connection week. Also make sure they are making solid contact. One other thing is that the wire colors coming from my 2005 wrangler are backwards from conventional wiring colors. The black (with color accent stripe) wire from the Jeep connected to the white wire on my light and the white wire (with color accent stripe) from my Jeep connected to the black wire on the light. Hope one of these two ideas helps.

 

[02GreenTJ]

Try cleaning up the four contact pads that make the electrical connection when the tail gate is closed. Two will be on the door and two on the Jeep tub. There may be some corrosion or something else making the connection week. Also make sure they are making solid contact. One other thing is that the wire colors coming from my 2005 wrangler are backwards from conventional wiring colors. The black (with color accent stripe) wire from the Jeep connected to the white wire on my light and the white wire (with color accent stripe) from my Jeep connected to the black wire on the light. Hope one of these two ideas helps.

I did that earlier today and then it it worked thanks though!